On Saturday March 5th, 2022 SDF will kick off its TOPS-20 Boot Camp series
on https://twitch.tv/sdfpubnix at 1PM Pacific Time (9PM GMT). Registration
is open at https://twenex.org/?bootcamp which includes access to SDF's
XKL Toad-2 and is offered at no cost.

If you cannot attend an archive of the live stream (approximately
1 hour long) will be posted to the fediverse via SDF's Peertube instance,
https://toobnix.org

Looking forward to doing a "TOPS-20 Boot Camp for VMS Users", though any User
of any operating system background is certainly welcome, kid.

"Stephen M. Jones" <smj@ma.sdf.org> writes:
>On Saturday March 5th, 2022 SDF will kick off its TOPS-20 Boot Camp series
>on https://twitch.tv/sdfpubnix at 1PM Pacific Time (9PM GMT). Registration
>is open at https://twenex.org/?bootcamp which includes access to SDF's
>XKL Toad-2 and is offered at no cost.
>
>If you cannot attend an archive of the live stream (approximately
>1 hour long) will be posted to the fediverse via SDF's Peertube instance,
>https://toobnix.org
>
>Looking forward to doing a "TOPS-20 Boot Camp for VMS Users", though any User
>of any operating system background is certainly welcome, kid.
>

Can you refresh my memory on the advantages and disadvantages of the PDP-10
vs. the VAX-11/780? From a technical standpoint, not from a nostalgia or DEC politics
standpoint? My migration at the time was from a PDP-8 to PDP-11 to VAX-11.

On Thu, 03 Mar 2022 14:30:52 GMT
scott@slp53.sl.home (Scott Lurndal) wrote:

> Can you refresh my memory on the advantages and disadvantages of the
> PDP-10 vs. the VAX-11/780? From a technical standpoint, not from a

PDP-10 was a 36 bit mainframe that (usually) ran TOPS.
VAX-11/780 was a 32 bit mini that (usually) ran VMS.

--
Steve O'Hara-Smith
Odds and Ends at http://www.sohara.org/

Ahem A Rivet's Shot <steveo@eircom.net> writes:
>On Thu, 03 Mar 2022 14:30:52 GMT
>scott@slp53.sl.home (Scott Lurndal) wrote:
>
>> Can you refresh my memory on the advantages and disadvantages of the
>> PDP-10 vs. the VAX-11/780? From a technical standpoint, not from a
>
> PDP-10 was a 36 bit mainframe that (usually) ran TOPS.
> VAX-11/780 was a 32 bit mini that (usually) ran VMS.
>

What were the advantages, if any, of one family over the other family?

I'm quite aware of the hardware specifications.

How does TOPS DCL compare with VMS DCL?

Ahem A Rivet's Shot <steveo@eircom.net> writes:

> On Thu, 03 Mar 2022 14:30:52 GMT
> scott@slp53.sl.home (Scott Lurndal) wrote:

>> Can you refresh my memory on the advantages and disadvantages of the
>> PDP-10 vs. the VAX-11/780? From a technical standpoint, not from a

> PDP-10 was a 36 bit mainframe that (usually) ran TOPS.
> VAX-11/780 was a 32 bit mini that (usually) ran VMS.

There is not such thing as "TOPS". There were 2 operating systems available
from DEC for the PDP-10 architecture, named "Tops-10" and "TOPS-20". (There
were others, such as MIT AI Lab's ITS, the Stanford AI Lab's WAITS, and BBN's
TENEX.)

Tops-10 was the older system, a direct development of the monitor developed for
the PDP-6. It featured a wide array of device types, including realtime
capabilities, and a very low level I/O model in which the programmer had to
know details of the device(s) for which she was writing (buffer sizes, how many
buffers to specify for best operation, etc.). System calls were created using
hardware instruction traps ("Unimplemented User Opcodes" or UUOs).

TOPS-20 was created for the third generation PDP-10, based on the research OS
TENEX from BBN (which was created to explore demand-paged virtual memory on the
first generation PDP-10). The only direct I/O access was to disks and tapes;
everything else was mediated through the PDP-11/40 front end processor (or
other PDP-11/34 processors for things like DECnet). There was only a single
system call instruction, JSYS "Jump to SYStem", with massive internal dispatch
tables to handle every contingency; I/O was handled by means of particular JSYS
calls, and internally handled by the page mapping hardware.

ITS started as an experiment on the PDP-6, and used the same model for I/O as
the DEC monitor, although the details and implementations were sui generis.

WAITS grew out of DEC's PDP-6 monitor, with updates to the PDP-10 version until
1972, at which time the two went their separate ways. WAITS used the same I/O
model as the DEC monitor, although hardware I/O instructions were available to
user mode programs without privilege escalation (for use with specialized
hardware like robot arms).

--
Rich Alderson news@alderson.users.panix.com
Audendum est, et veritas investiganda; quam etiamsi non assequamur,
omnino tamen proprius, quam nunc sumus, ad eam perveniemus.
--Galen

scott@slp53.sl.home (Scott Lurndal) writes:

> Ahem A Rivet's Shot <steveo@eircom.net> writes:
>> On Thu, 03 Mar 2022 14:30:52 GMT
>> scott@slp53.sl.home (Scott Lurndal) wrote:

>>> Can you refresh my memory on the advantages and disadvantages of the
>>> PDP-10 vs. the VAX-11/780? From a technical standpoint, not from a

>> PDP-10 was a 36 bit mainframe that (usually) ran TOPS.
>> VAX-11/780 was a 32 bit mini that (usually) ran VMS.

> What were the advantages, if any, of one family over the other family?

VMS ran on supported hardware after 1983.

The PDP-10 operating systems were mainframe oriented ab origine, unlike VMS.

> I'm quite aware of the hardware specifications.

> How does TOPS DCL compare with VMS DCL?

Again, there ain't no "TOPS".

Tops-10 offered a facility called "MIC" which allowed for programmed execution
of programs, but programs had to be written to handle whatever command line
arguments they might expect.

TOPS-20 offered an unrelated facility also called "MIC", which was less capable
than the Tops-10 facility of the same name. In addition, later versions of
TOPS-20 offered "PCL" ("Programmable Command Language"), with a very different
syntax than MIC, which originated at CMU but provided as an unsupported feature
by DEC.

The facilities offered by both OSes are unrelated to "DCL" as understood by VMS
and other PDP-11 oeprating systems.

--
Rich Alderson news@alderson.users.panix.com
Audendum est, et veritas investiganda; quam etiamsi non assequamur,
omnino tamen proprius, quam nunc sumus, ad eam perveniemus.
--Galen

On 03 Mar 2022 15:24:16 -0500
Rich Alderson <news@alderson.users.panix.com> wrote:

> Ahem A Rivet's Shot <steveo@eircom.net> writes:
>
> > On Thu, 03 Mar 2022 14:30:52 GMT
> > scott@slp53.sl.home (Scott Lurndal) wrote:
>
> >> Can you refresh my memory on the advantages and disadvantages of the
> >> PDP-10 vs. the VAX-11/780? From a technical standpoint, not from a
>
> > PDP-10 was a 36 bit mainframe that (usually) ran TOPS.
> > VAX-11/780 was a 32 bit mini that (usually) ran VMS.
>
> There is not such thing as "TOPS". There were 2 operating systems
> available from DEC for the PDP-10 architecture, named "Tops-10" and
> "TOPS-20". (There were others, such as MIT AI Lab's ITS, the Stanford AI
> Lab's WAITS, and BBN's TENEX.)

Yes I was using TOPS as a shorthand for "TOPS-10 or TOPS-20".

--
Steve O'Hara-Smith
Odds and Ends at http://www.sohara.org/

Rich Alderson <news@alderson.users.panix.com> writes:
>scott@slp53.sl.home (Scott Lurndal) writes:
>
>> Ahem A Rivet's Shot <steveo@eircom.net> writes:
>>> On Thu, 03 Mar 2022 14:30:52 GMT
>>> scott@slp53.sl.home (Scott Lurndal) wrote:
>
>>>> Can you refresh my memory on the advantages and disadvantages of the
>>>> PDP-10 vs. the VAX-11/780? From a technical standpoint, not from a
>
>>> PDP-10 was a 36 bit mainframe that (usually) ran TOPS.
>>> VAX-11/780 was a 32 bit mini that (usually) ran VMS.
>
>> What were the advantages, if any, of one family over the other family?
>
>VMS ran on supported hardware after 1983.

I was using VMS 1979-1983.

>
>The PDP-10 operating systems were mainframe oriented ab origine, unlike VMS.

VMS wasn't designed as a batch system, so far as I'm aware, although
it could certainly serve as such.

>
>> I'm quite aware of the hardware specifications.
>
>> How does TOPS DCL compare with VMS DCL?
>
>Again, there ain't no "TOPS".

Correction noted. Let's abstract from the jargon and talk more
generically about the user interface. Pros and Cons of MIC/PCL
vs. DCL.

Note that I spent most of the 80's writing mainframe operating
systems for Burroughs, so I've both batch and TS experience.
You've used one of the Burroughs boxen at the LCM, yourself.

>
>The facilities offered by both OSes are unrelated to "DCL" as understood by VMS
>and other PDP-11 oeprating systems.

Generically, then. How does the interactive user experience differ
between the Decsystem-10/20 and the VAX-11/780. I've read quite a few
PDP-10 advocates claiming superiority, but I've never seen any
data to back it up other than "I prefer this to that" or "I'm pissed
because DEC management killed Jupiter".

On Thu, 03 Mar 2022 15:33:04 -0500, Rich Alderson wrote:

> scott@slp53.sl.home (Scott Lurndal) writes:
>
>> Ahem A Rivet's Shot <steveo@eircom.net> writes:
>>> On Thu, 03 Mar 2022 14:30:52 GMT scott@slp53.sl.home (Scott Lurndal)
>>> wrote:
>
>>>> Can you refresh my memory on the advantages and disadvantages of the
>>>> PDP-10 vs. the VAX-11/780? From a technical standpoint, not from a
>
>>> PDP-10 was a 36 bit mainframe that (usually) ran TOPS.
>>> VAX-11/780 was a 32 bit mini that (usually) ran VMS.
>
>> What were the advantages, if any, of one family over the other family?
>
> VMS ran on supported hardware after 1983.

It is also true to say that it ran on supported hardware in 1977.

--
Using UNIX since v6 (1975)...

Use the BIG mirror service in the UK:
http://www.mirrorservice.org

I would like to apologize for confusing VMS users with my joke/reference.
Though Rich has provided some excellent background into the development of
TOPS-20. He was there and still is.

The "TOPS-20 Boot Camp for VMS Users" was in reference to the parody
in "Alice's PDP-10" which has a passage that goes a little like this:

....
And I put down my keyboard, and I switched buffers, and there ...
in the other buffer... centered in the other buffer... away from
everything else in the buffer... in parentheses, capital letters,
in reverse video, read the following words:

"Kid, have you taken the ``VMS for TOPS-20 managers'' course yet?"

I walked over to the man and I said "Mister, you got a lot of damned
gall asking me if I've taken the ``VMS for TOPS-20 managers'' course
yet. I mean... I mean... I mean, I'm sitting here on the bench, I'm
sitting here on the LCG SIG bench, 'cause you want to know if I'm
braindamaged enough trade my PDP-10 for partial credit on a system
that doesn't even handle filename completion after being a litterbug."

He looked at me and said "Kid, the front office don't like your kind,
so we're going to put you on our VAX/VMS mailing list." And friends,
somewhere down in the NE43 receiving room is a large trash barrel with
a big sign on it that says "VAX/VMS documents".
....

Hence the title of the SDF event: "TOPS-20 Boot Camp for VMS Users". And
it's really not just for VMS Users, but anyone interested in TOPS-20. There
will likely be more comparisons with Linux (a wildly popular operating system)
rather than with VMS (a mildly popular operating system).

You can hack anything that you want, with TECO and DDT.

References: https://www.hactrn.net/sra/alice/alices.pdp10

Scott Lurndal <scott@slp53.sl.home> wrote:
> "Stephen M. Jones" <smj@ma.sdf.org> writes:
>> On Saturday March 5th, 2022 SDF will kick off its TOPS-20 Boot Camp series
>> on https://twitch.tv/sdfpubnix at 1PM Pacific Time (9PM GMT). Registration
>> is open at https://twenex.org/?bootcamp which includes access to SDF's
>> XKL Toad-2 and is offered at no cost.
>>
>> If you cannot attend an archive of the live stream (approximately
>> 1 hour long) will be posted to the fediverse via SDF's Peertube instance,
>> https://toobnix.org
>>
>> Looking forward to doing a "TOPS-20 Boot Camp for VMS Users", though any User
>> of any operating system background is certainly welcome, kid.
>>
>
> Can you refresh my memory on the advantages and disadvantages of the PDP-10
> vs. the VAX-11/780? From a technical standpoint, not from a nostalgia or DEC politics
> standpoint? My migration at the time was from a PDP-8 to PDP-11 to VAX-11.
>

I’ve used both, although my -10 knowledge is 50 years old and not as
in-depth as I’d like. I’d say that the PDP-10 was more RISCy, and a
programmer’s dream to program in MACRO.

--
Pete

Scott Lurndal <scott@slp53.sl.home> wrote:
> Rich Alderson <news@alderson.users.panix.com> writes:
>> scott@slp53.sl.home (Scott Lurndal) writes:
>>
>>> Ahem A Rivet's Shot <steveo@eircom.net> writes:
>>>> On Thu, 03 Mar 2022 14:30:52 GMT
>>>> scott@slp53.sl.home (Scott Lurndal) wrote:
>>
>>>>> Can you refresh my memory on the advantages and disadvantages of the
>>>>> PDP-10 vs. the VAX-11/780? From a technical standpoint, not from a
>>
>>>> PDP-10 was a 36 bit mainframe that (usually) ran TOPS.
>>>> VAX-11/780 was a 32 bit mini that (usually) ran VMS.
>>
>>> What were the advantages, if any, of one family over the other family?
>>
>> VMS ran on supported hardware after 1983.
>
> I was using VMS 1979-1983.
>
>>
>> The PDP-10 operating systems were mainframe oriented ab origine, unlike VMS.
>
> VMS wasn't designed as a batch system, so far as I'm aware, although
> it could certainly serve as such.
>
>>
>>> I'm quite aware of the hardware specifications.
>>
>>> How does TOPS DCL compare with VMS DCL?
>>
>> Again, there ain't no "TOPS".
>
> Correction noted. Let's abstract from the jargon and talk more
> generically about the user interface. Pros and Cons of MIC/PCL
> vs. DCL.
>
> Note that I spent most of the 80's writing mainframe operating
> systems for Burroughs, so I've both batch and TS experience.
> You've used one of the Burroughs boxen at the LCM, yourself.
>
>>
>> The facilities offered by both OSes are unrelated to "DCL" as understood by VMS
>> and other PDP-11 oeprating systems.
>
> Generically, then. How does the interactive user experience differ
> between the Decsystem-10/20 and the VAX-11/780. I've read quite a few
> PDP-10 advocates claiming superiority, but I've never seen any
> data to back it up other than "I prefer this to that" or "I'm pissed
> because DEC management killed Jupiter".
>
>
It would have to be hard to tell, since the VAX hardware was a lot faster
than the PDP-10. I enjoyed working with both systems.

--
Pete

> You can hack anything that you want, with TECO and DDT.

Excepting, of course, Alice.

De

Peter Flass <peter_flass@yahoo.com> writes:
> It would have to be hard to tell, since the VAX hardware was a lot faster
> than the PDP-10. I enjoyed working with both systems.

For the first N years, VAXes were much slower than the faster 10's.
Faster VAXes appeared later, and eventually overtook the 10 mostly due
to improved chip technology. The main VAX for a long time was the
original 11/780 (introduced 1977) which was the canonical 1 MIP machine.
A KL-10 (introduced 1975) was maybe 3x that, about equivalent(?) to the
VAX 8600 that that came out in 1984.

I don't know about today, but legend has it that a few 11/780's were
kept operational for decades after that model's obsolescence, to serve
as benchmark hosts for MIPs rating of newer cpus.

drb@ihatespam.msu.edu (Dennis Boone) writes:
> > You can hack anything that you want, with TECO and DDT.
>
>Excepting, of course, Alice.

Thanks Arlo.

On Fri, 04 Mar 2022 22:14:54 +0000, Scott Lurndal wrote:

> drb@ihatespam.msu.edu (Dennis Boone) writes:
>> > You can hack anything that you want, with TECO and DDT.
>>
>>Excepting, of course, Alice.
>
> Thanks Arlo.

I have the album and the movie.

--
Using UNIX since v6 (1975)...

Use the BIG mirror service in the UK:
http://www.mirrorservice.org

Bob Eager <news0009@eager.cx> writes:

> On Thu, 03 Mar 2022 15:33:04 -0500, Rich Alderson wrote:

>> scott@slp53.sl.home (Scott Lurndal) writes:

>>> What were the advantages, if any, of one family over the other family?

>> VMS ran on supported hardware after 1983.

> It is also true to say that it ran on supported hardware in 1977.

The 4th generation of the PDP-10 line was canceled in May, 1983, although the
customer base was large enough (financially speaking) to force Digital to
provide hardware support until 1988 and software support until 1993, but there
were no more sales by Digital of PDP-10 hardware to new customers after May
1983.

So an advantage of the VAX and VMS over the PDP-10 systems was support after
1983. Got it?

--
Rich Alderson news@alderson.users.panix.com
Audendum est, et veritas investiganda; quam etiamsi non assequamur,
omnino tamen proprius, quam nunc sumus, ad eam perveniemus.
--Galen

Ahem A Rivet's Shot <steveo@eircom.net> writes:

> On 03 Mar 2022 15:24:16 -0500
> Rich Alderson <news@alderson.users.panix.com> wrote:

>> There is not such thing as "TOPS". There were 2 operating systems
>> available from DEC for the PDP-10 architecture, named "Tops-10" and
>> "TOPS-20". (There were others, such as MIT AI Lab's ITS, the Stanford AI
>> Lab's WAITS, and BBN's TENEX.)

> Yes I was using TOPS as a shorthand for "TOPS-10 or TOPS-20".

A bad habit, since the two operating systems shared exactly zero features and
exactly zero code.

--
Rich Alderson news@alderson.users.panix.com
Audendum est, et veritas investiganda; quam etiamsi non assequamur,
omnino tamen proprius, quam nunc sumus, ad eam perveniemus.
--Galen

Bob Eager <news0009@eager.cx> writes:

>On Fri, 04 Mar 2022 22:14:54 +0000, Scott Lurndal wrote:

>> drb@ihatespam.msu.edu (Dennis Boone) writes:
>>> > You can hack anything that you want, with TECO and DDT.
>>>
>>>Excepting, of course, Alice.
>>
>> Thanks Arlo.

>I have the album and the movie.

What about the 8x10 glossy photographs with circles and arrows...?

--
A host is a host from coast to coast...............wb8foz@panix.com
& no one will talk to a host that's close..........................
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

On 4 Mar 2022 22:17:58 GMT
Bob Eager <news0009@eager.cx> wrote:

> I have the album and the movie.

How about the anniversary recordings ? I have the thirtieth which
has some fun Nixon references.

--
Steve O'Hara-Smith
Odds and Ends at http://www.sohara.org/

I am of course, late to the game. And the bootcamp have already
happened. So people might already know the answers and comments I'm
about to give, but anyway...

On 2022-03-03 21:33, Rich Alderson wrote:
> scott@slp53.sl.home (Scott Lurndal) writes:
>
>> Ahem A Rivet's Shot <steveo@eircom.net> writes:
>>> On Thu, 03 Mar 2022 14:30:52 GMT
>>> scott@slp53.sl.home (Scott Lurndal) wrote:
>
>>>> Can you refresh my memory on the advantages and disadvantages of the
>>>> PDP-10 vs. the VAX-11/780? From a technical standpoint, not from a
>
>>> PDP-10 was a 36 bit mainframe that (usually) ran TOPS.
>>> VAX-11/780 was a 32 bit mini that (usually) ran VMS.
>
>> What were the advantages, if any, of one family over the other family?
>
> VMS ran on supported hardware after 1983.

True. Or perhaps you should have said "developed after 1983". Not sure
if I'd classify that as an advantage when trying to do some kind of
comparison between the systems, though.

> The PDP-10 operating systems were mainframe oriented ab origine, unlike VMS.

Not entirely sure what you mean by that, Rich.
As you noted, Tops-10 originated in the monitor for the PDP-6. Is that
enough to call it mainframe? And is that a good thing? Tops-10 wasn't
very fancy or capable in some ways, even though it had some nifty things.
TOPS-20 is a completely different thing (as you also observed), with a
much more capable and nice design, if you ask me. If definitely have
some features and capabilities that VMS lacked. But was it more
mainframe-oriented? What does that even mean? TOPS-20 was probably worse
from an execution point of view than VMS, requiring more resources to
get the job done. But VMS isn't really any kind of batch oriented
environment either...

>> I'm quite aware of the hardware specifications.
>
>> How does TOPS DCL compare with VMS DCL?
>
> Again, there ain't no "TOPS".

[...MIC and and PCL text deleted...]
I think the question wasn't about scripting, but interactive use here.
Tops-10 or TOPS-20 did not have DCL. I can't remember what the
interactive command line interpreter was called in Tops-10, but in
TOPS-10 it's EXEC.
EXEC is for most people a much nicer environment than DCL. Command name
completion, filename completion, guide words, interactive help... It's
just so much nicer than DCL.

Scripting wise, it's much more muddled.

Apart from user interaction, some things are better, and some are worse
in VMS. It's hard to answer a generic question like "how were they
different", or what advantages one had over the other, unless we want to
just talk specific technical details. Because the rest is pretty subjective.

Johnny

On 2022-03-04 22:23, Paul Rubin wrote:
> Peter Flass <peter_flass@yahoo.com> writes:
>> It would have to be hard to tell, since the VAX hardware was a lot faster
>> than the PDP-10. I enjoyed working with both systems.
>
> For the first N years, VAXes were much slower than the faster 10's.

Not really. The KL10 was about 1.5 MIPS, while the original VAX-11/780
was 1 MIPS.

Speed parity was basically achieved with the VAX-11/785. After that, the
VAXen just were becoming faster.

The PDP-10 was never a speed daemon. It was helped a lot by being
offloaded for terminal I/O by the front end processor. But with the
spreading of ethernet, all of that work started moving back to the
PDP-10 itself, at which point you really felt the pain. 40 users on a
-2060 was usually not all that much fun, I can tell you. Heck, even 20
was painful.

> Faster VAXes appeared later, and eventually overtook the 10 mostly due
> to improved chip technology. The main VAX for a long time was the
> original 11/780 (introduced 1977) which was the canonical 1 MIP machine.
> A KL-10 (introduced 1975) was maybe 3x that, about equivalent(?) to the
> VAX 8600 that that came out in 1984.

KL-10 was about 1.5x. The 8600, introduced in 1984 was 4x the 11/780,
and was noticeably faster than the KL-10.

> I don't know about today, but legend has it that a few 11/780's were
> kept operational for decades after that model's obsolescence, to serve
> as benchmark hosts for MIPs rating of newer cpus.

I think I heard such stories, but I never put any value to them. Another
story/problem is that the original MIPS definition was also based on a
specific version of OS and compiler. And as these evolved, the
VAX-11/780 actually became significantly faster than 1 MIPS. Which
exposed a problem with the whole MIPS definition. And also meant keeping
any VAXen around for reference was pretty pointless.

And that's a big reason DEC themselves never used MIPS. They instead
talked about VUPs. Where a VAX-11/780 was by definition 1 VUP. And it
was more properly based on the actual processing speed, and not
depending on various software.

Johnny

Johnny Billquist <bqt@softjar.se> wrote:
> I am of course, late to the game. And the bootcamp have already
> happened. So people might already know the answers and comments I'm
> about to give, but anyway...
>
> On 2022-03-03 21:33, Rich Alderson wrote:
>> scott@slp53.sl.home (Scott Lurndal) writes:
>>
>>> Ahem A Rivet's Shot <steveo@eircom.net> writes:
>>>> On Thu, 03 Mar 2022 14:30:52 GMT
>>>> scott@slp53.sl.home (Scott Lurndal) wrote:
>>
>>>>> Can you refresh my memory on the advantages and disadvantages of the
>>>>> PDP-10 vs. the VAX-11/780? From a technical standpoint, not from a
>>
>>>> PDP-10 was a 36 bit mainframe that (usually) ran TOPS.
>>>> VAX-11/780 was a 32 bit mini that (usually) ran VMS.
>>
>>> What were the advantages, if any, of one family over the other family?
>>
>> VMS ran on supported hardware after 1983.
>
> True. Or perhaps you should have said "developed after 1983". Not sure
> if I'd classify that as an advantage when trying to do some kind of
> comparison between the systems, though.
>
>> The PDP-10 operating systems were mainframe oriented ab origine, unlike VMS.
>
> Not entirely sure what you mean by that, Rich.
> As you noted, Tops-10 originated in the monitor for the PDP-6. Is that
> enough to call it mainframe? And is that a good thing? Tops-10 wasn't
> very fancy or capable in some ways, even though it had some nifty things.
> TOPS-20 is a completely different thing (as you also observed), with a
> much more capable and nice design, if you ask me. If definitely have
> some features and capabilities that VMS lacked. But was it more
> mainframe-oriented? What does that even mean? TOPS-20 was probably worse
> from an execution point of view than VMS, requiring more resources to
> get the job done. But VMS isn't really any kind of batch oriented
> environment either...
>
>>> I'm quite aware of the hardware specifications.
>>
>>> How does TOPS DCL compare with VMS DCL?
>>
>> Again, there ain't no "TOPS".
>
> [...MIC and and PCL text deleted...]
> I think the question wasn't about scripting, but interactive use here.
> Tops-10 or TOPS-20 did not have DCL. I can't remember what the
> interactive command line interpreter was called in Tops-10, but in
> TOPS-10 it's EXEC.
> EXEC is for most people a much nicer environment than DCL. Command name
> completion, filename completion, guide words, interactive help... It's
> just so much nicer than DCL.
>
> Scripting wise, it's much more muddled.
>
> Apart from user interaction, some things are better, and some are worse
> in VMS. It's hard to answer a generic question like "how were they
> different", or what advantages one had over the other, unless we want to
> just talk specific technical details. Because the rest is pretty subjective.
>
> Johnny
>

It’s been a lot of years, but doesn’t VMS DCL have command-line completion?
(sorry for all the included text, I can’t seem to get this darn thing to
select text to delete)

--
Pete

Johnny Billquist <bqt@softjar.se> wrote:
> On 2022-03-04 22:23, Paul Rubin wrote:
>> Peter Flass <peter_flass@yahoo.com> writes:
>>> It would have to be hard to tell, since the VAX hardware was a lot faster
>>> than the PDP-10. I enjoyed working with both systems.
>>
>> For the first N years, VAXes were much slower than the faster 10's.
>
> Not really. The KL10 was about 1.5 MIPS, while the original VAX-11/780
> was 1 MIPS.
>
> Speed parity was basically achieved with the VAX-11/785. After that, the
> VAXen just were becoming faster.
>
> The PDP-10 was never a speed daemon. It was helped a lot by being
> offloaded for terminal I/O by the front end processor. But with the
> spreading of ethernet, all of that work started moving back to the
> PDP-10 itself, at which point you really felt the pain. 40 users on a
> -2060 was usually not all that much fun, I can tell you. Heck, even 20
> was painful.
>
>> Faster VAXes appeared later, and eventually overtook the 10 mostly due
>> to improved chip technology. The main VAX for a long time was the
>> original 11/780 (introduced 1977) which was the canonical 1 MIP machine.
>> A KL-10 (introduced 1975) was maybe 3x that, about equivalent(?) to the
>> VAX 8600 that that came out in 1984.
>
> KL-10 was about 1.5x. The 8600, introduced in 1984 was 4x the 11/780,
> and was noticeably faster than the KL-10.
>
>> I don't know about today, but legend has it that a few 11/780's were
>> kept operational for decades after that model's obsolescence, to serve
>> as benchmark hosts for MIPs rating of newer cpus.
>
> I think I heard such stories, but I never put any value to them. Another
> story/problem is that the original MIPS definition was also based on a
> specific version of OS and compiler. And as these evolved, the
> VAX-11/780 actually became significantly faster than 1 MIPS. Which
> exposed a problem with the whole MIPS definition. And also meant keeping
> any VAXen around for reference was pretty pointless.
>
> And that's a big reason DEC themselves never used MIPS. They instead
> talked about VUPs. Where a VAX-11/780 was by definition 1 VUP. And it
> was more properly based on the actual processing speed, and not
> depending on various software.
>
> Johnny
>

IBM never used MIPS either, but rated processors relative to each other. I
always thought they did this to avoid comparisons to other vendors’
machines, but it was probably as much because it was meaningless, as you
say.

--
Pete

Johnny Billquist <bqt@softjar.se> writes:
> The KL10 was about 1.5 MIPS, while the original VAX-11/780 was 1 MIPS.

Ah ok, for some reason I had thought the KL10 was faster than that.
EIther way: "36 bits -- a full DEC" ;-)